Key Concepts: Wave-Particle Duality

Wave-Particle Duality

• Light and matter exhibit both wave-like and particle-like behavior, depending on the experiment.

Light as a Wave

• Interference, diffraction, and polarization are explained by wave theory.
• Young's double-slit experiment showed light forms interference fringes — a wave property.

Light as a Particle (Photon)

• The photoelectric effect showed light ejects electrons as if it were discrete packets (photons).
• Photon energy: E = hf, where h = 6.63 × 10⁻³⁴ J·s (Planck's constant).

Matter Waves (de Broglie)

• All particles have an associated wavelength: λ = h/p = h/(mv).
• For macroscopic objects, λ is incredibly tiny (undetectable). For electrons, λ is measurable and significant.
• Electron diffraction confirmed that particles can behave as waves.